Transgenic glyphosate-resistant oilseed rape (Brassica napus) as an invasive weed in Argentina: detection, characterization, and control alternatives

Abstract

Abstract The presence of glyphosate-resistant oilseed rapepopulations in Argentina was detected and characterized.The resistant plants were found as weeds in RR soybeansand other fields. The immunological and molecular analysisshowed that the accessions presented the GT73 transgenicevent. The origin of this event was uncertain, as the cultivationof transgenic oilseed rape cultivars is prohibited in Argentina.This finding might suggest that glyphosate resistance couldcome from unauthorized transgenic oilseed rape crops cultivatedin the country or as seed contaminants in imported oilseedrape cultivars or other seed imports. Experimentationshowed that there are alternative herbicides for controllingresistant Brassica napus populations in various situationsand crops. AHAS-inhibiting herbicides (imazethapyr,chlorimuron and diclosulam), glufosinate, 2,4-D, fluroxypyrand saflufenacil proved to be very effective in controllingthese plants. Herbicides evaluated in this research wereemployed by farmers in one of the fields invaded with this biotype and monitoring of this field showed no evidence of itspresence in the following years.